In nearly 35 years of owning various cars, mostly cheap ones, I haven't had too many problems. In fact I have had more problems with the more expensive ones I have bought.
Best/most reliable was a Subaru Legacy Turbo (actually the most expensive car I have ever owned). Only things that went wrong with it over and and above normal wear items was the T-union on the headlamp washer pipes failed, and it needed a new battery at nine years and 95,000 miles (not unreasonable, I feel).
Others included an Audi Coupe, Audi 90 20V, and Audi 100 which were all utterly reliable. Also various BL/Austin Rover/Rover cars that never let me down - including the much-maligned Marina, and Rover 25. Plus the legendary £275 Volvo V70 bought with 283,000 miles on, used for three years including many 500+ mile round trips, and sold (in better condition) for £600 three years later with 307,000 miles up.
Worst cars - Citroen BX 1.6. Unspeakably awful AND hideously unreliable. Lasted three months.
Rover 825 D - comfortable, good on fuel, good to drive. But that engine (the main non-Rover bit, it was made by VM in Italy) was ALWAYS needing something doing to it. Drove me potty, and I was glad to get shot of it
Volvo S8- T6 - a very silly car. Very fast, supremely comfortable, amazing at eating huge distances with ease. Bizarrely unreliable, to the point where my local Volvo specialist and I became good friends, it was always weird dealer-only things like the indicator control unit (a circuit board behind the steering wheel that had to be programmed to the car - that will be £400, Sir), or the 'throttle unit' (a mere £450 to you, good Sir). Or the ABS control unit - would have been £1200+ VAT for a new one. It was fixed in a morning by taking it out and dabbing the power inlet solder joints with a soldering iron ("They all do that, Sir. It's a feature" was the consensus from the Volvo forum)
My mechanic said "I think it is that the T6 engine is too powerful for the car"
Just bought a Volvo XC70 - this one has a few faults, I have rejected it with the dealer, who is not responding to my messages and letters. Legal action is imminent....